The US Army Ballistic Research Laboratory (BRL) is presently conducting a program of shock isolation/mitigation experiments in connection with the development of hardened tactical shelters by the Army. The objective is to investigate techniques for reducing severity of air blast induced shock loads transmitted into sensitive equipment installed within shelters. A number of full scale shock survivability tests have already taken place using large military shock tube facilities and explosive nuclear simulation events at White Sands Missile Range (WSMR).The program has been mostly ad hoc thus far, adapting existing shock isolation devices to specific hardened shelters, but the information obtained is fairly generic. Shelter/rack acceleration and displacement data have been generated and analyzed for spectral content. Selected isolation devices have been proven effective in reducing transmitted shock loads. The shelter/isolator/rack mounting configurations have been varied to determine optimal designs.